1. Field of the Invention
The present invention relates to a write-once optical disc and a method and apparatus for recording/reproducing data on/from the write-once optical disc, and more particularly, to a method and apparatus for recording final management information in a defect management area of the write-once disc and a method and apparatus for utilizing the same to perform recording/reproducing for the write-once optical disc.
2. Discussion of the Related Art
As an optical recording medium, optical discs on which high-capacity data can be recorded are widely being used. Among them, a new high-density optical recording medium (HD-DVD), for example, a Blu-ray disc, has been recently developed for recording and storing high-definition video data and high-quality audio data for a long term period.
The Blu-ray disc is the next generation HD-DVD technology and the next generation optical recording solution, and has an excellent capability to store data more than the existing DVDs. Recently, a technical specification of international standard for HD-DVD has been established.
Related with this, various standards for a write-once Blu-ray disc (BD-WO) are being prepared following the standards for a rewritable Blu-ray disc (BD-RE).
FIG. 1 schematically illustrates the structure of a recording area of a rewritable BD-RE. The BD-RE shown in FIG. 1 is a single layer disc having one recording layer. The disc includes from the inner periphery thereof a lead-in area, a data area and a lead-out area. The data area is provided with an inner spare area (ISA0) and an outer spare area (OSA0) respectively disposed at the inner and outer peripheries to replace defective areas on the disc, and a user data area for recording user data therein and provided between the spare areas.
As data is recorded on the rewritable blue-ray disc (BD-RE), if there exists a defective area in the user data area, data recorded in the defective area is transferred to and recorded in a portion of the spare area such as the ISA0 or OSA0. This portion of the spare area is also known as a replacement area. Additionally, the position information of the defective area and the position information of the corresponding replacement area are recorded in defect management areas (DMA1˜DMA4) provided in the lead-in/out areas to perform defect management. The BD-RE has a cluster as a minimal recording part recorded thereon. One cluster is composed of total 32 sectors, and one sector is composed of 2048 bytes. In particular, the BD-RE allocates and uses 32 clusters as the defect management area (DMA).
Since rewriting of data can be performed in any area of the rewritable disc, the entire area of the disc can be used randomly irrespective of the specific recording manner. Also, since the defect management information can be written, erased and rewritten repeatedly even in the defect management areas (DMAs), it does not matter even though only a small size of the defect management area is provided.
FIG. 2 illustrates the structure of a DMA in the BD-RE of FIG. 1. Each of the DMA1 through DMA4 has the structure shown in FIG. 2. In this regard, defect management information stored in the DMA1 is recorded also in each of the other DMAs (DMA2, DMA3 and DMA4) so that this information is not lost and is available even if one of the DMAs becomes defective.
As shown in FIG. 2, in the rewritable single layer disc (BD-RE), one DMA is composed of total 32 clusters. Four heading clusters (Cluster 1˜Cluster 4) of the DMA are provided as an area in which disc definition structure (DDS) information is repeatedly recorded four times, one cluster for one DDS. Remaining Clusters 5 to 32 are provided as an area in which a defect list (DFL) is recorded seven times, four clusters for one DFL.
A variety of information required for disc management is recorded in the DDS, which includes position information (Pointer DFL, hereinafter referred to as “P_DFL”) for informing a position of a valid DFL. Accordingly, in case that a recording/reproducing apparatus intends to record and manage the defective area of the disc as the DFL, the DFL is recorded at a 1st position of DFL (Cluster 5 to Cluster 8) of the DMA, and the position information (P_DFL) on the DFL is recorded in the DDS. Hereafter, if a new DFL is to be recorded, the new DFL is overwritten at the 1st position of DFL (Cluster 5 to Cluster 8).
However, in case that the above procedure is continuously performed, the 1st position of DFL (area in which the DFL is recorded) may become a damaged area. At this time, the new DFL is recorded at a valid 2nd position of DFL (Cluster 9 to Cluster 12) of the DMA, and the position information on this new DFL (New P_DFL) is recorded in the DDS. Accordingly, 3rd to 7th positions of DFLs (Cluster 13 to Cluster 32) of the DMA first remain to be in the unrecorded state in which recording has not yet been made, and then are sequentially recorded with the next new DFL. For instance, if the 2nd position of DFL is damaged, the DFL is newly recorded at the 3rd position of DFL (Cluster 13 to Cluster 16), and the position information on this new DFL (New P_DFL) is recorded in the DDS.
FIG. 3 illustrates the structure of a dual layer BD-RE having two recording layers (Layers 0 and 1). The disc has four DMAs (DMA1˜DMA4) each having total 64 clusters. Two DMA parts in the Layers 0 and 1 constitute one DMA. For instance, the DMA 1 is composed of the two DMA parts (“DMA1” and “DMA1”) in the Layers 0 and 1.
FIG. 4 illustrates the structure of each defect management area of the dual layer BD-RE of FIG. 3. As in the single layer BD-RE, the same information is recorded in each DMA, and each DMA includes a DDS recorded in each of Clusters 1˜4, a reserved area at Clusters 5˜8, and Clusters 9˜64 for recording the DFLs. In the dual layer disc of FIG. 4, recording is made on the basis of the same concept as that of the recording method of the single layer DMA of FIG. 2, but differs in that one DFL is recorded with 8 clusters (e.g., Clusters 9 to 16) and that the reserved area is provided between the DDS (Clusters 1 to 4) and the DFL (Clusters 9 to 64). Clusters 9 to 64 are provided as an area in which the DFL is recorded for seven times, 8 clusters for one DFL recording.
In the above rewritable disc, overwriting can be made in any one of the recording areas of the disc such that a recording manner is not much limited. However, in a write-once disc, since writing can be made only once on any area on the disc, the recording manner is not only much limited, but also the defect management becomes an important matter especially when data is recorded on a high-density write-once disc such as a BD-WO.
Accordingly, there is a need for a method of recording and managing defect management information in a write-once optical disc such as a BD-WO, which takes into consideration the characteristics of the disc such as the write-once characteristic. Further, a case in which recording can be performed on the disc should be generally distinguished from a “final” case in which recording is no longer performed. And in such cases, a method of recording and managing the defect management information is needed.
Since any currently published regulation on the existing write-once optical discs (e.g., CD-R, DVD-R) does not address a case in which the defect management is performed, a new unified regulation on defect management for the new write-once optical discs is urgently needed to address the above-mentioned requirements associated with the disc.